EP1778331A1 - Evaporators and evaporation methods - Google Patents

Abstract

This invention relates to an evaporator comprising a casing ( 1; 21 ) and a heater ( 7; 27 ). Gas is supplied through an inlet ( 4; 24 ) and discharged through an outlet ( 5; 25 ). The casing forms an evaporating space ( 2; 22 ) and a heating space ( 3; 33 ) heated by the heater ( 7; 27 ). The evaporating space ( 2; 22 ) may be partially filled with a liquid ( 16; 36 ). The gas flows from the inlet ( 4; 24 ) via the heating space ( 3; 23 ) to the evaporating space ( 2; 22 ) and further to the outlet ( 5; 25 ). This invention moreover relates to an evaporator comprising an outer and an inner tub. The outer tub is heated. The inner tub may contain a water reserve and is inserted into the outer tub. The upper side of the bottom of the outer tub ( 8; 28 ) or the underside of the bottom of the inner tub ( 10; 30 ) is made of a soft elastic material. The invention finally relates to corresponding methods.

Description

 Evaporator as well as evaporation process

The invention relates to evaporators of the type mentioned in the preambles of claims 1 and 19 and to methods of the type mentioned in the preambles of claims 13 and 21. More specifically, the invention relates to humidifiers for respirators in a broader sense, including CPAP , Bi-level and anti-snarl area.

An evaporator and an evaporation method according to the preambles of the independent claims are known for example from DE 199 36 499 A1, DE 200 10 553 U1 or DE 101 51 397 C1.

The ventilators include so-called CPAP devices that are used to treat apneas (respiratory arrest) during sleep. For this purpose, the CPAP (continuous positive airway pressure) therapy was developed. A CPAP device generates by means of a compressor or a turbine a positive overpressure up to about 30 mbar and preferably applies this via a humidifier, via a hose and a nasal mask in the respiratory tract of the patient. This overpressure is intended to ensure that the upper respiratory tracts remain completely open during the entire night and thus no apneas occur (DE 198 49 571 A1). This is also referred to as pneumatic splinting of the respiratory tract. A humidifier used in conjunction with the CPAP device prevents the patient from drying out of the mucous membranes.

From DE 101 05 383 C2 an anti-snoring device is known, in which instead of a nose mask or face mask, a pair of aerial goggles is used. The advantage of this anti-snoring device is the increased wearing comfort, resulting from the avoidance of a nose mask or face mask and the use of thinner hoses. Also, air goggles are similar to oxygen goggles, which are already produced inexpensively in large quantities.

DE 199 36 499 A1 describes a device for breathing gas humidification for CPAP devices. The moistening device comprises a refill unit formed from a tub element and a pot part coupled thereto, which can be removed from an erection housing. The tub element and the cup part are tightly connected. In the cup part is in conjunction with a Partition wall formed a liquid reservoir, which contains the majority of the intended for humidification of the respiratory gas supply of water. In the tray member disposed below the tub member, a separate humidification area is formed in which only a small part of the water supply is contained. The height of the water in the tub element is maintained at a predetermined level via a metering device. In the course of the gradual evaporation of the water in the tub element water is refilled successively or continuously from the liquid reservoir. The breathing gas is blown through a breathing gas inlet opening through the upper portion of the tub member to a breathing gas outlet opening. The bottom portion of the tub member is heated by a heater.

DE 200 10 553 U1 describes a similar humidifier for ventilators, as described in DE 199 36 499 A1. Also in the humidifier from DE 200 10 553 U1 air is passed over the surface of a heated water reservoir. Instead of the refill unit, which consists of a tub element and a cup part, a water container is used, which consists essentially of one part.

Further similar humidifiers are known from DE 101 51 397 C1 and German Utility Model 202004004 115.4.

It is an object of the invention to provide a vaporizer and an evaporation method, in which fast operational readiness is achieved.

This object is achieved by the teaching of the independent claims.

Preferred embodiments of the invention are subject of the dependent claims.

Due to the low heat capacity of the gas supplied compared to the heat capacity of the liquid reservoir, a significant evaporation is achieved virtually immediately after startup.

By heating the incoming gas is the entire

Liquid surface including the inlet area used for the evaporation of liquid molecules or atoms. On the other hand - as with When the liquid is heated, the gas in the entry area is heated to the temperature of the liquid so that the entry area is not effectively used for evaporation because colder gas is less likely to pick up liquid molecules or atoms.

A removable inner tub, which serves as a liquid reservoir, facilitates the refilling of liquid and the cleaning of the evaporator.

Pressure tightness ensures that a vaporizer for the gas behaves like a piece of pipe.

Through a uniform heating of the outer tub, the required heating power is passed through a large area. This leads to a lower temperature on the heater.

Advantageous for a cheap production is that no seal is required between the inner tub and the lid, but even a narrow gap can remain free. Rather, the different gas resistance between the narrow gap and the passage is sufficient for the majority of the gas to flow through the passage.

Further, in the embodiments of the present invention, neither the inlet nor the outlet require a moving seal, which keeps manufacturing costs low and increases reliability.

The heat transfer from the heated outer tub to the inner tub with the liquid is assisted by the fact that the gas moves between the outer and inner tub, if possible in the entire gap. By lateral material transport in a turbulent gas flow, the thermal conductivity of moving gases is higher than of stationary gases. Additionally, heat is transported through the passage by the gas flow and transferred from the bottom of the outer tub to the bottom of the inner tub. All this ensures good thermal coupling between heater, gas and liquid, which means lower heater temperatures are sufficient to compensate for evaporative cooling. Low heater temperatures also reduce calcification problems. By arranging the passage in the direction of rotation of the gas seen in front of the inlet, it is achieved that the gas moves over the entire gap length.

A high relative velocity between liquid and gas promotes evaporation of liquid molecules or atoms.

An inner tub with two cylindrical areas and an intermediate waist-shaped area fits well in an oval outer tub. The gap between the inner and outer trough may be narrow in the cylindrical regions, which ensures good heat transfer due to the smaller distance between the inner and outer trough and the high flow velocity of the gas and the resulting turbulence. In the waisted area, the distance between the inner and outer troughs is larger, so here the gap is wide enough for a standard finger, so that the inner trough can be easily removed for cleaning or refilling water.

The two trays and the lid can advantageously be made of stainless steel. Stainless steel keeps high temperatures compared to plastics and is additionally biocompatible. In particular, fire protection additives for plastics are usually not biocompatible.

Hereinafter, preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawings. Showing:

Fig. 1 is a plan view of an evaporator according to the invention;

Fig. 2 is a side view of the evaporator shown in Fig. 1;

Fig. 3 is a plan view of another evaporator according to the invention;

Fig. 4 is a side view of the evaporator shown in Fig. 3; and

FIGS. 5 to 7 show vertical sections through various embodiments of the inner tub according to the invention. Figs. 1 and 2 show an embodiment of an evaporator according to the invention. The housing 1 of the evaporator consists essentially of three parts, namely an outer tub 8, an inner tub 10 and a lid 9. The inner tub 10 is in the outer tub 8, so that touch the two trough floors and also on the floors Heat can be transferred, in Figure 1 cover 9 is only partially shown in the unfolded position. Cover 9 may be attached to outer tub 8 with hinges 17.

Between the lateral surfaces of the two troughs, a gap is formed, which is referred to as a heating chamber 3. The enclosed by the inner tub 10 and the lid 9 space is referred to as evaporation space 2. In the lower part of the evaporation space is a liquid, usually water 16. Outside of the outer tub 8, so both on the bottom and the outer surface, a heater 7 is attached.

Gas, mostly air, is supplied to the evaporator via inlet 4. The gas first passes into boiler room 3, where it flows around inner tub 10 almost once counterclockwise. In this case, the gas heats up on the lateral surface of the outer tub 8 and transmits part of the heat also to the inner tub 10. Subsequently, the gas flows through passage 11 from the heating chamber 3 in the evaporation space 2. By fixtures 12 in the lid 9, their position at closed lid 9 is shown in dashed lines in Figure 1, it is achieved that the gas is conducted as possible over the entire liquid surface. This promotes the evaporation of the liquid. Finally, the gas is discharged via outlet channel 13 and outlet 5.

Another embodiment may be constructed in mirror symmetry to the embodiment illustrated in FIGS. 1 and 2 so that the gas flows clockwise around inner tub 10, such as in the embodiment illustrated in FIGS. 3 and 4.

The only high quality and moving seal is located between outer

Well 8 and cover 9. Although the visible in Fig. 2 gap between the inner tub 10 and cover 9 should be as narrow as possible, so that the gas defined by

Passage 11 flows. On the other hand, it affects the functions of the evaporator not essential, for example, when half of the gas flows through the gap and the other half through the passage 11.

As can be clearly seen in FIG. 1, the inner tub 10 has a bone-shaped outline with two cylindrical regions 14 and an intermediate waist-shaped region 15. The purpose of the waist-shaped region 15 is above all that standard fingers have space in the waist-shaped region 15 between the inner and outer trough. This in turn ensures that the inner tub can be conveniently removed from the outer tub for refilling or cleaning.

The waist-shaped region 15 also ensures that the gas flow in the heating chamber 3 becomes more turbulent. Therefore, the heat transfer from the outer surface of the outer tub via the gas in the heating chamber 3 on the outer surface of the inner tub is not worse to the extent that would suggest the greater distance between the two lateral surfaces in the waisted area.

In order for the gas to cover as much as possible the entire liquid surface, passage 11 is located in one and the outlet channel 13 in the other cylindrical area.

Figures 3 and 4 show another embodiment of the inventive evaporator. In contrast to the evaporator shown in Figures 1 and 2, the housing 21 with outer tub 28, inner tub 30 and lid 29 are substantially rotationally symmetrical in this evaporator. Again, gas is blown through an inlet 24 into an annular heating chamber 23 between the lateral surfaces of the inner and outer trough. After the gas has flowed almost once around the inner tub 30, it passes through the passage 31 into the evaporation space 22 within the inner tub 30 and sweeps across the surface of a liquid, such as water 36. Thereafter, the wetted or liquid molecules or atoms become liquid Enriched gas from the center of the two tubs through outlet channel 33 to outlet 25 passed. This embodiment can also be mirrored.

Lid 29 may have helical internals 32 which are shown in phantom in Fig. 3 to utilize the entire liquid surface for evaporation. As shown in Figures 1 to 4, sharp corners are avoided in particular in the tubs, but also in the lids to facilitate the cleaning of the parts. In particular, the edges between the lateral surfaces and the bottoms of the tubs are rounded. This ease of cleaning makes it possible to install the evaporator firmly in a larger unit, thus avoiding moving seals at the inlet and outlet.

The outer and inner tubs and the lid can be made of stainless steel. Stainless steel is biocompatible and tolerates high temperatures. In contrast, fire protection materials in plastics are usually not biocompatible.

Heater 7, for example, from wound heating wire, which is fixed and insulated with tape or consist of a Kapton foil heater.

The inner trough, shown only schematically in FIGS. 1 to 4, can also be designed as shown in one of FIGS. 5 to 7. FIGS. 5 to 7 show vertical sections through inner trays 10 or 30.

In the embodiments illustrated in Figures 5 to 7, the bottom of the inner tub is made of an elastic, biocompatible material, such as silicone. This has the advantage that the bottom of the inner tub adapts to the bottom of the outer tub and reduces an air gap between the inner and outer tub and is ideally reduced to zero over the entire floor area. This reduces the thermal resistance between the two floors and further lowers the heater temperature.

Although the bottom of the inner tub should be soft to conform to the bottom of the outer tub, the walls of the inner tub must have some rigidity so that the inner tub can be gripped from the outer tub when being removed.

Also, the bottom of the outer tub may be made of or coated with a soft, resilient material such as silicone. Such an outer tub can be combined with an inner tub made of stainless steel or with an inner tub whose bottom is made of silicone. Fig. 5 shows an embodiment of the inner tub, wherein the bottom 41 made of silicone, the walls 42, however, are made of stainless steel.

Fig. 6 shows an embodiment of the inner tub, wherein the bottom 51 and the lower part of the lateral surface 52 made of silicone, the upper part of the lateral surface 53 5 is made of stainless steel. The upper edge 54 of the lateral surface may be bent.

In the embodiment shown in Fig. 7, the entire inner tub made of silicone 61. The upper edge of the tub is widened to increase the stability here. In order to further increase the stability, a wire 10 62, in particular a spring wire can be embedded in the upper edge.

Due to the heating of the gas, a significant evaporation of the liquid is achieved almost immediately after startup. After startup, the rate of evaporation increases until the liquid reaches equilibrium temperature. To speed up this process, it may be beneficial to preheat for three to four minutes before starting up.

Although evaporators according to the invention are used mainly as a humidifier. However, this is not a necessary feature, since it is known from German Patent Application 103 22 964.7 to use a gas mixture with a composition deviating from air or to add air to active substances such as aerosols, fragrances or medicine. Also, the water can be added to an active ingredient such as seawater additive, so that the generic term "liquid" is justified.

The invention has been explained in detail above with reference to preferred embodiments. However, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit of the invention. Therefore, the scope of protection is defined by the following claims and their equivalents.

Replacement Blade (RULE 26) LIST OF REFERENCE NUMBERS

1 housing 24 inlet

2 evaporation room 25 outlet

5 3 boiler room 27 heater

4 inlet 25 28 outer tub

5 outlet 29 lid

7 heaters 30 inner tub

8 outer tub 31 passage

10 9 Lid 32 installations

10 inner tub 30 33 outlet duct

11 passage 36 water

12 installations 41 floor

13 outlet channel 42 lateral surface

15 14 cylindrical areas 51 bottom

15 waist-shaped area 35 52 lower lateral surface

16 water 53 upper lateral surface

17 hinge 54 bent edge

21 Housing 61 Silicon

20 22 Evaporation room 62 wire

23 boiler room 40

Replacement Blade (RULE 26)

Claims

claims 1. evaporator with: a housing (1; 21) having an inlet (4; 24) for supplying a gas and an outlet (5; 25) for discharging the supplied gas; wherein the housing (1; 21) forms an evaporation space (2; 22) which partially with a Liquid (16; 36) can be filled; and a heater (7; 27); characterized in that the housing (1; 21) forms a heating space (3; 23) which is in thermal contact with the heater (7; 27), the inlet (4; 24) being connected to the heating space (3; 23) , the boiler room (3; 23) with the Evaporating space (2; 22) and the evaporation space (2; 22) is connected to the outlet (5; 25) so that gas from the inlet (4; 24) via the boiler room (3; 23) to the evaporation space (2; 22) and further to the outlet (5; 25) can flow. A vaporizer according to claim 1, characterized in that the housing (1; 21) comprises an open-topped inner trough (10; 30) for receiving the liquid (16; 36), the inner trough (10; 30) defining the evaporation space (2; 22) limited. A vaporizer according to any one of the preceding claims, characterized in that the housing (1; 21) comprises an outer tub (8; 28) and a lid (9; 29), the outer tub (8; 28) and the lid (9, 29) close pressure tight. 4. evaporator according to claim 3, characterized in that the heater (7; 27) on the outside of the outer tub (8; 28) is mounted so that it heats the outer tub (8; 28) largely uniformly. 5. evaporator according to claim 1 or 4, characterized in that the housing comprises an outer trough (8; 28), an inner trough (10; 30) and a cover (9; 29), wherein the outer trough (8; 28 ) and the lid (9; 29) close pressure-tight, wherein the inner trough (10; 30) in the outer The lid (9, 29) and inner tub (10, 30) surround the evaporation space (2, 22) and the heating space (3; 23) is located between the inner and outer troughs (10, 8; 30, 28) and additionally delimited by the lid (9; 29). 6. evaporator according to claim 5, characterized in that the inlet (4; 24) is formed so that in the heating chamber (3; 23) entering gas tangentially, ie approximately parallel to the walls of the inner and outer tub (10, 8, 30, 28), enters the heating chamber, so that by the shaping of the inlet (4, 24) a circulation direction of the gas in the heating chamber to the inner tub (10; 30). 7. evaporator according to claim 6, characterized in that a passage (11; 31) in the inner trough (10; 30), wherein the passage (11; 31) the heating space (3; 23) with the evaporation space (2 22) and wherein the passage is in the direction of rotation just before the inlet (4; 24). 8. evaporator according to one of claims 3 to 7, characterized in that the cover (9; 29) internals (12; 32) to the gas line, which in operation for a high relative speed between the liquid (16; 36) and the supplied Gas worry. 9. evaporator according to claim 7, characterized in that the lateral surface of the inner trough (10) has two cylindrical portions (14) which are connected by a waist-shaped portion (15), wherein the passage (11) in the one cylindrical portion is located and an outlet channel (13) from the center of the other cylindrical Area to the outlet (5) extends. 10. evaporator according to claim 7, characterized in that the lateral surfaces of the inner and outer trough (10, 8) are cylindrical and an outlet channel (33) from the center of the inner trough (30) to the outlet (25). 11. evaporator according to one of the above claims, characterized in that the inner tub (10; 30), the outer tub (8; 28) and / or the lid (9; 29) are made of stainless steel. A vaporizer according to any one of the preceding claims, characterized in that the outer tub (8; 28) of stainless steel and the bottom surface (41; 51; 61) of the inner tub (10; 30) are made of silicone. 13. Evaporation process with: Passing (2; 22) a gas over a liquid surface; marked by: Heating (7; 27) the gas before passing it over the liquid surface. 14. Evaporation method according to claim 13, characterized by: Passing the gas through a heating space (3; 33) between an inner tub (10; 30) and an outer tub (8; 28); Heating the outer tub (8; 28); and Passing the gas in an evaporation space (2; 22) across the liquid surface; wherein the evaporation space and the liquid (16; 36) are located within the inner tub (10; 30). The evaporation method according to claim 14, further characterized by: Tangential introduction of the gas into the heating chamber (3; 33), so that the gas flows around the inner tub (10; 30), thereby establishing a circulation direction. 16. The evaporation method according to claim 15, further characterized by: Passing the gas from the boiler room (3; 33) in the evaporation space (2; 22) at a point which, viewed in the direction of rotation, is just before the point at which the gas is introduced into the boiler room (3; 33). 17. An evaporation process according to any one of claims 14 to 16, characterized in that the gas is guided spirally in a cylindrical region of the evaporation space (2; 22) to the center of the cylindrical region and from there through an outlet channel (13; 33) to a 5 outlet (5; 25) is passed. 18. Evaporation process according to one of claims 14 to 17, characterized by: Inserting the inner tub (10; 30) into the outer tub (8; 28); and Adjusting the shape of the bottom of the inner tub (10; 30) to the shape of the bottom of the outer tub (8; 28) at each insertion. 19th evaporator with: an outer tub (8; 28); a heater (7; 27) thermally coupled to the outer tub (8; 28); 15 an inner tub (10; 30) which may be inserted into the outer tub (8; 28) and receive a supply of water (16; 36); characterized in that the top of the bottom of the outer tub (8; 28) or the bottom of the bottom of the inner tub (10; 30) is made of a soft, resilient material. 20 20. evaporator according to claim 19, characterized in that the soft, elastic material is silicone. 21. Evaporation process with: Filling an inner tub (10; 30) with a liquid (16; 36); Inserting the inner tub (10; 30) into an outer tub (8; 28); 25 heating (7; 27) the outer tub (8; 28); characterized in that each time one of the following steps is performed: Fitting the underside of the bottom (41; 51; 61) of the inner tub (10; 30) to the top of the bottom of the outer tub (8; 28); or Adjusting the top of the bottom of the outer tub (8; 28) to the Bottom of the bottom of the inner tub (10; 30).